Performance enhancements:
- Faster load times for content on the Firefox Home page
- Faster page load times by loading either from the networked cache or
the cache on the user’s hard drive (Race Cache With Network)
- Improved graphics rendering using Off-Main-Thread Painting (OMTP) for Mac users (OMTP for Windows and Linux was released in Firefox 58)

Added support for W3C specs for pointer events and improved platform integration with added device support for mouse, pen, and touch screen pointer input

Added the Ecosia search engine as an option for German Firefox

Added the Qwant search engine as an option for French Firefox

Added settings in about:preferences
to stop websites from asking to send notifications or access your
device’s camera, microphone, and location, while still allowing trusted
websites to use these features

Update:
To get the update now, select "Help" from the Firefox menu, then pick "About Firefox." Mac users need to select "About Firefox" from the Firefox menu. If you do not use the English language version, Fully Localized Versions are available for download.